Jonathan Welsh answers readers' questions about automobiles

Q: I have been using 91-octane fuel with 10% ethanol in my 2010 Infiniti G37 for 3 years. (The manual says this is OK.) However, I am wondering if there might be any long-term negative effects on the engine or exhaust system.

—Rod Brown, Playa Del Rey, Calif.

A:Many critics say that ethanol, an alcohol commonly mixed into gasoline, attacks fuel pumps and other parts, and attracts water that can cause corrosion. However, problems have been rare in my experience, and I believe much of the anti-ethanol hype is just that.

Cars have been running on the 10% ethanol mix for a long time and newer models like your Infiniti were built for it. Following the owner's-manual recommendations should keep you out of trouble.

Q:As vehicles' center consoles grow, my legs are cramped. I hold on to my GMC Envoy because there is no offending console. Any others I should look at?

—Ed Singer, Rockville, Md.

A: Decades ago, when "bench" seats were popular in family cars, consoles between the front seats were rare. They were the mark of luxury cars that sacrificed practicality in the name of style. Today it is difficult to find even an economy car without a console. Your best bet is a pickup truck or a minivan.

Q:Toyota recommends changing the oil and filter at 10,000-mile intervals on my new 2013 Camry. My thinking is that this is a very long time to go between changes.

—Chuck McComish, Bettendorf, Iowa

A: Years ago I would have said to replace the oil more often, no matter what the car maker suggested. However, my mechanic recently told me drivers throughout Europe where synthetic oil has been the standard for a long time laugh at how often Americans change their cars' oil. He and other experts tell me that 10,000 miles between changes is no big deal for synthetics, so I am rethinking my old ways. Stick with Toyota's schedule.

Q: I would like to replace my 2003 Toyota 4Runner with a vehicle that has similar cargo space and reliability, but a softer, more comfortable ride.

—Keith Milner, El Cajon, Calif.

A: The new 4Runner is one of a dying breed: the truck-based midsize SUV. Most of its old rivals, including the Nissan Pathfinder and Ford Explorer, have converted into crossovers with car-style chassis that deliver better handling and a relatively smooth, quiet ride. They are among the natural replacements for the 4Runner, as is Toyota's own Highlander.

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